Question

When a green iron salt is heated strongly sets colour finally changes to be brown and odour of buring sulphur is given out.
1)Name the iron salt
2)Name the gas evolved
3)Name the type of reaction that takes place
4)write chemical equation for the reaction involved ​

Answer 1

A)the name of the salt:
The Iron salt in this case is Iron Sulphate( commonly existing as Iron sulphate heptahydrate and known as ferrous sulphate or  green vitriol)

b) type of reaction:
The reaction that take place when iron sulphate is heated is known as thermal decomposition. A decomposition reaction
The iron sulphate decomposes to give Iron(III)oxide, sulphur dioxide and sulphur trioxide.

c)The chemical equation.

      2 FeS04(s) ----------> Fe2O3 (s) + SO3(g) + SO2(g)

The burning sulphur smell is due to the sulphur oxides while the black compound is ferric oxide; which can have varied colors ranging between brown, red, yellow or orange color.